So-called disk or plate yarn brakes of this kind are known in many versions in textile technology. Especially advantageous modern constructions are described for instance in German Patents DE 41 04 663 C1 and DE 43 01 507 C2, both owned by the present Assignee. They all have pin-like bearing means, which are disposed, extending through the central opening of the at least one brake element, and on which at least this brake element is rotatably supported. There are embodiments in which the diameter of a bearing pin forming the pin-like bearing means is substantially less than the diameter of the central opening of the brake elements, so that the brake elements are suspended, swinging freely, from the bearing pin. Other versions use pin-like bearing means embodied in the form of a bolt, whose diameter is only slightly smaller than the opening diameter of the brake elements (see for instance FIG. 5 of DE 41 04 663 C1). The brake elements are provided with plastic bearing bushes, to improve their bearing conditions on the bolt or on a ceramic bearing bush slipped onto this bolt. The loading means pressing the brake elements elastically together are either compression springs, in the conventional manner, or else permanent magnetic rings are used for this purpose, which are placed in the shell-like, ferromagnetic brake elements.
In order to guide the yarn to be braked properly between the brake elements, yarn deflection pins, yarn eyelets and other such yarn guide means are provided, depending on the particular construction involved. As a rule at least some of these means are provided directly on the retention means that support the bearing pin or bolt for the brake elements. The arrangement is usually such that the bearing pin or bolt is floatingly suspended from the retention means. Moreover, in those embodiments in which the brake elements, as noted, are suspended swinging from a bearing pin of small diameter, the brake elements are assigned lateral stop elements spaced apart from them, which limit the otherwise free motion of the brake elements in the axial direction and guard against the brake elements escaping from their bearing means.
The retention means with which the yarn brake is secured to the housing of a yarn supply apparatus are all comparatively complicated, which is true particularly when the yarn brake cooperates with a vibration generating device that sets the brake elements into vibrational motions, which are primarily oriented crosswise to the bearing axis (DE 41 04 663 C1) or in a direction at right angles to it (DE 4 4 09 450 C2). Because the brake elements or their bearing means are set into vibration, the lint deposits, soiling and so forth that otherwise occur, originating in yarns that are hard to process, are largely averted. This provision has therefore gained excellent acceptance in the industry.
Yarn brakes of the above type are fundamentally mass-produced articles, which means that the production cost is a decisive factor in determining commercial success. Moreover, they must be easy to maintain and especially easy to clean, which as a rule is done by blowing a stream of compressed air at them. It should be avoided that the brake elements might escape from their bearing means or that blown-off dirt particles, lint and the like might collect in corners or dead spaces of retaining elements, bearing parts, etc. of the yarn brake and thus over the long term threaten the operational reliability of the yarn brake.
Moreover, a yarn brake must often meet the demand for easy assembly and disassembly, in addition to the capability of convenient, effective cleaning.